Search results for "Charm"
showing 10 items of 390 documents
Precision measurement of D meson mass differences
2013
Using three- and four-body decays of D mesons produced in semileptonic b-hadron decays, precision measurements of D meson mass differences are made together with a measurement of the D-0 mass. The measurements are based on a dataset corresponding to an integrated luminosity of 1.0 fb(-1) collected in pp collisions at 7 TeV. Using the decay D-0 -> K+K-K-pi(+), the D-0 mass is measured to be M(D-0) = 1864.75 +/- 0.15 (stat) +/- 0.11 (syst) MeV/c(2). The mass differences M(D+) - M(D-0) = 4.76 +/- 0.12 (stat) +/- 0.07 (syst) MeV/c(2), M(D-s(+)) - M(D+) = 98.68 +/- 0.03 (stat) +/- 0.04 (syst) MeV/c(2) are measured using the D-0 -> K+K-pi(+)pi(-) and D-(s)(+) -> K+K-pi(+) modes.
Heavy quark spin symmetry and SU(3)-flavour partners of the X (3872)
2013
In this work, an Effective Field Theory (EFT) incorporating light SU(3)-flavour and heavy quark spin symmetries is used to describe charmed meson-antimeson bound states. At Lowest Order (LO), this means that only contact range interactions among the heavy meson and antimeson fields are involved. Besides, the isospin violating decays of the X(3872) will be used to constrain the interaction between the D and a (D) over bar* mesons in the isovector channel. Finally, assuming that the X(3915) and Y(4140) resonances are D* (D) over bar* and D-s* (D) over bar (s)* molecular states, we can determine the four Low Energy Constants (LECs) of the EFT that appear at LO and, therefore, the full spectrum…
Inclusive D-Meson Production at the LHC
2012
I present predictions for the inclusive production of $D$ mesons at the CERN LHC in the general-mass variable-flavor-number scheme at next-to-leading order. Numerical results are compared to data where available, and uncertainties to scale variations, parton distribution functions and charm mass are discussed. I point out that measurements at large rapidity have the potential to pin down models of intrinsic charm.
QCD sum rule determination of the charm-quark mass
2011
QCD sum rules involving mixed inverse moment integration kernels are used in order to determine the running charm-quark mass in the $\bar{MS}$ scheme. Both the high and the low energy expansion of the vector current correlator are involved in this determination. The optimal integration kernel turns out to be of the form $p(s) = 1 - (s_0/s)^2$, where $s_0$ is the onset of perturbative QCD. This kernel enhances the contribution of the well known narrow resonances, and reduces the impact of the data in the range $s \simeq 20 - 25 GeV^2$. This feature leads to a substantial reduction in the sensitivity of the results to changes in $s_0$, as well as to a much reduced impact of the experimental u…
Transverse momentum dependence of D-meson production in Pb-Pb collisions at √sNN = 2.76 TeV
2016
The production of prompt charmed mesons D0 , D+ and D∗+, and their antiparticles, was measured with the ALICE detector in Pb-Pb collisions at the centre-of-mass energy per nucleon pair, √ sNN, of 2.76 TeV. The production yields for rapidity |y| < 0.5 are presented as a function of transverse momentum, pT, in the interval 1–36 GeV/c for the centrality class 0–10% and in the interval 1–16 GeV/c for the centrality class 30–50%. The nuclear modification factor RAA was computed using a proton-proton reference at √ s = 2.76 TeV, based on measurements at √ s = 7 TeV and on theoretical calculations. A maximum suppression by a factor of 5–6 with respect to binary-scaled pp yields is observed for the…
Measurement of CP asymmetry in D 0 → K - K + and D 0 → π - πdecays
2014
Time-integrated $CP$ asymmetries in $D^0$ decays to the final states $K^- K^+$ and $\pi^- \pi^+$ are measured using proton-proton collisions corresponding to $3\mathrm{\,fb}^{-1}$ of integrated luminosity collected at centre-of-mass energies of $7\mathrm{\,Te\kern -0.1em V}$ and $8\mathrm{\,Te\kern -0.1em V}$. The $D^0$ mesons are produced in semileptonic $b$-hadron decays, where the charge of the accompanying muon is used to determine the initial flavour of the charm meson. The difference in $CP$ asymmetries between the two final states is measured to be \begin{align} \Delta A_{CP} = A_{CP}(K^-K^+)-A_{CP}(\pi^-\pi^+) = (+0.14 \pm 0.16\mathrm{\,(stat)} \pm 0.08\mathrm{\,(syst)})\% \ . \nonu…
Multiquark description of the D-sJ(2860) and D-sJ(2700)
2009
Within a theoretical framework that accounts for all open-charm mesons, including the D-0*(2308), the D-sJ*(2317), and the D-sJ(2460), we analyze the structure and explore possible quantum number assignments for the D-sJ(2860) and the D-sJ(2700) mesons reported by BABAR and Belle Collaborations. The open-charm sector is properly described if considered as a combination of conventional quark-antiquark states and four-quark components. All negative parity and 2(+) states can be understood in terms only of q (q) over bar components, however the description of the 0(+) and 1(+) mesons is improved whenever the mixing between two- and four-quark configurations is included. We analyze all possible…
"Table 9" of "Measurement of prompt D-meson production in p-Pb collisions at sqrt(sNN) = 5.02 TeV"
2015
Average of D0, D+, D*+ nuclear modification factors R(pPb) vs. pT.
"Table 5" of "Measurement of prompt D-meson production in p-Pb collisions at sqrt(sNN) = 5.02 TeV"
2015
Nuclear modification factor R(pPb) of prompt D0 mesons vs. pT measured in p-Pb collisions in the rapidity interval -0.96
"Table 7" of "Measurement of prompt D-meson production in p-Pb collisions at sqrt(sNN) = 5.02 TeV"
2015
Nuclear modification factor R(pPb) of D*+ mesons vs. pT measured in p-Pb collisions in the rapidity interval -0.96